Several types of child-resistant closures and packages have been proposed to resist or impede opening by a child. These packages may contain medications, household products and the like that can be harmful if not properly used. However, child-resistant packages also can impede opening by adults having reduced manual dexterity. Child-resistant closures and packages have been proposed that can be inverted or converted to a non-child-resistant mode of operation. However, such closures and packages are complex and/or expensive and/or difficult for a user to convert between child-resistant and non-child-resistant modes of operation. A general object of the present disclosure is to address one or more of these deficiencies in the prior art.
The present disclosure embodies a number of aspects that can be implemented separately from or in combination with each other.
A child-resistant closure, in accordance with one aspect of the present disclosure, includes a one-piece plastic shell having a base wall with a peripheral edge, an annular skirt, and a bistable snap-action toggle connection between the peripheral edge of the base wall and the skirt such that the skirt is adapted to be moved between two stable positions with respect to the base wall. At least one lug is disposed on the skirt or the base wall for engagement with cooperating structure in a child-resistant mode of operation in a first position of the skirt with respect to the base wall. The skirt is movable with respect to the base wall between the first position and a second position for selecting between child-resistant and non-child-resistant modes of operation of the closure. The bistable snap-action connection preferably includes a continuous annular wall connecting the peripheral edge of the base wall to the skirt, with the annular wall being outwardly conical in one position of the skirt and inwardly conical in the other position of the skirt with respect to the base wall. The annular wall preferably includes annular regions of reduced thickness connecting the annular wall to the skirt and the base wall. The closure preferably includes indicia that are covered by the skirt in one position of the skirt and uncovered by the skirt in the other position of the skirt with respect to the base wall for indicating to a user whether the closure is in the child-resistant or the non-child-resistant mode of operation.